This invention relates to electromagnetic relays of the type employing a core arranged in a coil and a yoke coupled to the core that at least partially extends beyond the coil to form an end face at its free end aligned essentially with a core pole face while forming a right angle with the axis of the coil. The invention, more particularly, relates to this type of relay wherein a flat armature is spring mounted on the end face of the yoke and forms with the core pole face a working air gap.
In a typical conventional relay of this kind, such as is described in the German patent document No. DE-GM 82 35 283, a plate-shaped armature is held by a bearing spring in front of the end face of the yoke, with the bearing spring itself being fastened on a yoke section relatively far removed from the end face, encompassing the entire bearing site arc-shaped and in its further course being firmly connected to the armature itself. The armature projects with its border edge beyond the outside of the yoke and has in the region of the bearing spring a cutout. With this kind of mounting, the armature does not have a definite roll-off site which can cause non-uniform flux transition. Furthermore, the bearing force is non-uniform.
In order to obtain with relays of this nature a defined bearing site, it is a conventional practice to bend the armature at an angle and let it roll off on a yoke knife-edge. This, practice, however, requires a relatively expensive adjustment step forth yoke and armature. Moreover, using an angle armature is possible only if sufficient space is available on the outside of the yoke for the projecting armature. One of the goals in miniaturizing relays is, however, to avoid such projecting movable parts for the sake of compactness of construction.